The invention pertains to games, puzzles and toys and more particularly to children's novelty puzzles which involve solving a mystery or story.
There are a wide variety of children's games, puzzles, toys and other novelties which primarily consist of cards. In addition to the most basic sports trading cards, there have been movie trading cards, the front faces of which are pictures of individual characters from the movie and the back faces of which have a portion of a scene from the movie or other illustration. On such cards, the user must purchase and collect the cards until he has all the cards that are required to assemble that scene or illustration.
There are, additionally, a variety of optical illusions and devices formed using different colored markings so that when viewed in a particular way or through a particular filter such as a color filter a certain image is perceived. Similar marking techniques have been used to create tests for various forms of color blindness.
One technique involves the use of a colored transparent sheet which acts as a filter tending to prevent the transmission of light rays of substantially different color than the filter. By example, if the primary color red is used for the filter it will absorb light of the other primary colors blue and green. Accordingly, objects which are otherwise blue or green will appear black (the absence of light transmission) whereas red objects will remain red and white objects will also be seen as red as the blue and green components of the white light are absorbed by the filter. Accordingly, on a white background, an image in blue may be surrounded and camouflaged by red markings so as to appear substantially illegible when viewed with the naked eye. When viewed through a red filter, however, it can be seen as a black image on a solid red background. It is further possible to use similar techniques whereby different images appear when the item is viewed through different primary or secondary color filters.
The basic technique has been used to hide clues or answers used with board games.